1. Field of the Invention
The present invention relates to disk drives and disk drive-containing devices having selectively controllable spindle motor spin up profiles. More particularly, the present invention relates to disk drives and disk drive-containing devices that are responsive to a command from a host device, adaptively responsive to a predetermined signal and/or to other internal or external stimuli to cause the spindle motor to spin up according to a selected one of a plurality of spin up profiles.
2. Description of the Prior Art and Related Information
It is conventional wisdom that, for disk drives, faster is better. When considering the spin up time of spindle motors of disk drives, the faster they are able to spin up to their target operating speed (e.g., 7200 rpm), the faster the drive will be ready to read and write data to and from the disk. Competitive forces, therefore, have conventionally steered the hard disk drive industry to develop drives that include spindle motors exhibiting fast spin up times. It has been found, however, that drives exhibit higher levels of acoustic noise during spin up than during normal operation when the spindle motor has reached its target speed. A balance has, therefore, been sought between competitive performance (fast spin up times) and acceptable levels of acoustical noise. In other words, hard disk drives designed for personal computers, workstations and servers are most often manufactured with spindle motors that are driven to spin up in the shortest period of time that does not produce objectionable noise levels.
The realm of applications in which disk drives are deployed, however, is growing. Increasingly, the high storage densities, low cost, modest power requirements and small size of current drives are having a synergistic effect upon the development and popularization of a wide variety of newly emergent digital consumer devices, such as digital cameras, mobile telephones, personal digital assistants (PDAs) and digital video recorders, to name a few. In such devices, it has been found that the acoustic noise inherent in short spindle motor spin up times frequently is perceived as a lack of quality and workmanship, if not an outright annoyance. Therefore, merely integrating conventional drives (wherein performance and acoustics are balanced) may not adequately address the fundamental differences between computer-based applications and consumer devices and appliances. For example, there may be instances in which a relatively high level of audible acoustic noise may be acceptable. Conversely, there may also be instances in which the acoustic noise generated by the spindle motor during spin up should be minimized.
Digital video recorder/players are illustrative of a class of consumer digital devices in which acoustic noise may affect consumer perception and acceptance thereof. For example, during times when the recorder/player is downloading information over a low bandwidth channel or in the middle of the night, it may be desirable, to avoid distracting or annoying the user, to operate the disk drive in the quietest mode possible. Alternatively, while a moderate level of audible drive noise may be undetectable when the ambient noise levels are high, such a moderate level of audible drive noise may become objectionable when the ambient acoustic levels lower. Notwithstanding such special purpose applications, it is anticipated that these units will in some instances serve as information processors, which at times will be demanding of hard disk performance. If disk drives are to be successfully integrated into everyday consumer devices such as digital video recorders and playback machines, cameras, musical instruments, kitchen appliances and the like, their existence and modes of operation must become uniformly unobtrusive, reliable, user-friendly and even adaptive, particularly with respect to the acoustic noise they generate.